Company lists · Data refreshed September 2026

Top 22 Climate tech startups based in Houston, United States

RevenueBase identified 45 climate tech startups headquartered in Houston, United States as of September 2026 and tracks 1,035 professional contacts across them, including 551 with verified work emails. New York is the largest hub.

This list covers climate tech startups headquartered in Houston, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review
45Companies
1,035Contacts tracked
551Verified emails
Explore this list → Free signup · no credit card · 500 free credits

The 22 largest climate tech startups based in Houston, United States

Ranked by team size
Top 22 of 45 climate tech startups based in Houston, United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to climate tech startups: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 2026501-1,000306 contacts →

Indirect evidence

“With decades of operating history and innovation across our trusted brands, Cimarron provides technology-driven emissions management solutions for the global energy system.”

Source: RevenueBase Database · checked Sep 19, 2026
2Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 2026201-500200 contacts →

Partial evidence

“Anew Climate is a global leader of diverse climate solutions, bringing innovative products and services to the public and private sectors to help reduce or offset their carbon…”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202651-20096 contacts →

Indirect evidence

“ClimeCo is an award-winning leader in decarbonization, empowering global organizations with customized sustainability pathways.”

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202651-20096 contacts →

Indirect evidence

“At E’kabel, we design and implement solutions that drive efficiency, sustainability, and performance across energy operations.”

Source: RevenueBase Database · checked Sep 19, 2026
5Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202611-5080 contacts →

Indirect evidence

“Syzygy Plasmonics is a technology company decarbonizing chemical production with its proprietary light-driven reactor technology.”

Source: RevenueBase Database · checked Sep 19, 2026
6Strong evidenceHouston, TX, United StatesHQ checked Sep 19, 2026n/a37 contacts →

Strong evidence

“Partnered with MIT and Greentown Labs, our mission is to train and develop the next generation of energy transition and climate tech entrepreneurs from some of the leading Texas…”

Source: RevenueBase Database · checked Sep 19, 2026
7Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 202651-20034 contacts →

Indirect evidence

“IHI Energy Solutions, a group company of IHI Corporation, creates value for our planet, clients and stakeholders by offering Engineering, Procurement and Project Management…”

Source: RevenueBase Database · checked Sep 19, 2026
8Partial evidenceHouston, United StatesHQ checked Sep 19, 20261-1015 contacts →

Partial evidence

“Macaw Energies combats global climate change by transforming biogas, flared, and stranded gases into affordable low-carbon energies.”

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-1015 contacts →

Indirect evidence

“Mars Materials, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
10Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-1011 contacts →

Indirect evidence

“Blue Sky Infrastructure is a Houston, Texas based company focused on providing infrastructure solutions to capture, transport, and geologically store CO2 safely and permanently…”

Source: RevenueBase Database · checked Sep 19, 2026
11Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-107 contacts →

Partial evidence

“Ecosphere Ventures is a Houston-based Pre-Seed through late-Seed stage fund focused on investing in transformative climatetech and sustainability solutions in the U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
12Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-106 contacts →

Indirect evidence

“Serving conscientious companies committed to reducing carbon emissions as part of the energy transition.”

Source: RevenueBase Database · checked Sep 19, 2026
13Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 202611-504 contacts →

Partial evidence

“Fidelis New Energy, LLC is a Houston-based climate positive infrastructure firm focused on creating and operating projects and systems in the decarbonization and sustainability…”

Source: RevenueBase Database · checked Sep 19, 2026
14Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-103 contacts →

Indirect evidence

“Noverram is a proud member of the United Nations Global Compact - United States Country Network A new world requires new ideas.”

Source: RevenueBase Database · checked Sep 19, 2026
15Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-102 contacts →

Indirect evidence

“WHAT WE DO We empower the carbon life cycle from inception to impact From project conception to market impact, we are your complete solution for premium carbon offsets.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-102 contacts →

Indirect evidence

“Enoverra provides engineering solutions to mitigate GHG emissions and transition towards more sustainable and renewable alternatives.”

Source: RevenueBase Database · checked Sep 19, 2026
17Indirect evidenceHouston, United StatesHQ checked Sep 19, 20261-102 contacts →

Indirect evidence

“Shipping generates one billion tons of GHG per year and meeting the “Net-Zero GHG Emissions from Global Shipping by 2050” goal demands swift technology development and upskilling…”

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-102 contacts →

Indirect evidence

“SDC Enerserve provides critical services needed to develop, own, and operate conventional and low-carbon, renewable energy and carbon reduction and storage businesses utilizing…”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-102 contacts →

Partial evidence

“Quantum New Energy (QNE) is a Climate Technology Company based in Houston, Texas, providing a data-driven sustainability platform.”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-101 contacts →

Indirect evidence

“NovaMark Energy Services, LLC is a company based in Houston, TX involved in developing Low Carbon Strategies for energy producers.”

Source: RevenueBase Database · checked Sep 19, 2026
21Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-101 contacts →

Indirect evidence

“Carbon-Focused Venture Capital”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261-101 contacts →

Indirect evidence

“The MH Alliance is a group of energy consultants based in the USA that offers a total solution to producing clean energy from seabed gas hydrates.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 22 of 45 climate tech startups based in Houston, United States

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 551 reachable decision-makers.

Free signup · no credit card

View the full list →

Climate tech startups based in Houston, United States at a glance

As of Sep 19, 2026
53.2%Verified-email coverage
23.0Average contacts per company
1-10Median size (employees)
113.3%Largest-city concentration · New York
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
31
11-50
7
51-200
5
201-500
1
501-1,000
1

Email recency for this list is measured across the whole United States list rather than for Houston, so it is reported there. Company counts and contact totals on this page are exact for Houston, over 45 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among climate tech startups, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Houston, United States whose own description of what they do matches “climate tech startups”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names climate tech startups), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among climate tech startups, and records with no verified work email. Companies headquartered outside Houston are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 551 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Climate tech startups by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names climate tech startups, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many climate tech startups are there based in Houston, United States?

RevenueBase identified 45 climate tech startups headquartered in Houston, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Cimarron, headquartered in Houston, tops this list with the largest team on record.

Which city has the most climate tech startups?

New York leads with 51 headquartered companies, followed by Houston (45) and San Francisco (39).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 551 verified decision-maker contacts tracked across these 45 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.

Ready to reach these companies? Verified emails and direct dials for all 45 climate tech startups based in Houston, United States. Start with a free account, no credit card.

Download this list →

Related lists

About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.